Debris collecting apparatus

ABSTRACT

Lawn and parking lot sweepers of the rotary brush type in which sweepings are discharged into bags are known. However, in such sweepers the debris generally is not compressed sufficiently prior to entering the bag. As a result, bags must be changed too frequently. The apparatus herein is provided with a single compression roller having mechanically actuated retractable fins for force filling a compression chamber. Debris from the compression chamber outlet is forced into the bag. Conveying means transport debris from a cylindrical brush or mower outlet to the compression roller.

United States Patent 1191 Doering Mar. 11, 1975 1 DEBRIS COLLECTING APPARATUS 1,088,043 2/1914 Strong 192/431 1,368,394 2 i921 G th ie..... Inventor: Charles W. Doering, CarkSVllle, m

2,860,750 11/1958 Avanzati 192/44 [73] Assignee: Brinly-Hardy Co., llnc., Louisville, FQREIGN PATENTS OR ppuc o s 183,259 9/1955 Germany 180/53 WA [22] Filed: Aug. 27, 1973 Primary Examiner-Allan D. Herrmann [2]] Appl' 391600 Attorney, Agent, or Firm-Frank C. Leach, Jr.

Related US. Application Data [62] Division of Ser. No. 268,064, June 30, 1972, Pat. No. [57] ABSTRACT Lawn and parking lot sweepers of the rotary brush type in which sweepings are discharged into bags are [52] 74/ zsgiz i known. However, in such sweepers the debris gener- [51] Int Cl F16! 41/16 ally is not compressed sufficiently prior to entering the [58] Fie'ld 74,13 bag. As a result, bags must be changed too frequently. 74/577 g 82 f The apparatus herein is provided with a single com- 6/ pression roller having mechanically actuated retractable fins for force filling a compression chamber. De [56] References Cited bris from the compression chamber outlet is forced UNITED STATES PATENTS 281,910 7/1883 Moore et a1. 74/577 S 12/1885 Cornog 81/63 11/1901 McKim 81/63 into the bag. Conveying means transport debris from a cylindrical brush or mower outlet to the compression roller.

10 Claims, 8 Drawing Figures PATENTEB MAR 1 3975 saw 2 of 2 1 DEBRIS COLLECTING APPARATUS This is a divisional application of application Ser. No. 268,064 AOH filed June 30, 1972, now Pat. No. 3,849,043.

This invention in one of its aspects relates to a sweeping apparatus of the cylindrical rotary brush type, capable of collecting grass cuttings, leaves,

and the like from lawns and grass fields. In another.

' operator of the apparatus to empty a collecting hopper or bin. Sweepings are urged in compacted form into a disposable or reusable bag.

Lawn sweepers are known in which sweepings are, discharged into bags. Such an apparatus is described in US. Pat. No. 3,229,320. In the collecting apparatus shown in US Pat. No. 3,229,320, the debris is conveyed by helical blades to a side outlet having a bag opening pulled over it, the bag being squeezed up in bellows-like fashion. The compressed bag rests on an apron having a circular end plate integral with it at its outside end. The apron-plate arrangement is slidable toward and away from the helical conveyor. To resist lateral movement of the apron away from the helical blades, a spring pressed tooth carried thereby rides in a plurality of inclined teeth. This keeps the bag compressed and offers some resistance as it is filling.

The sweeper described in U.S. Pat. No. 3,229,320 overcomes the problem of having to empty a hopper. It is, however, subject to certain disadvantages. Thus, the cylindrical sweeping element must rotate quite rapidly in order to throw debris up into the helix. In addition, even though the tension of the bag filling resistance element attached to the apron can be varied, debris compression is still not as a great as is desirable.

In accordance with this invention, a sweeper-bagger is provided, affording a much greater degree of compression of debris than has been obtainable in existing apparatus. The brush also need not revolve as rapidly in the apparatus herein. In addition, whereas a power unit can be incorporated in the machine, it operates effectively without such a unit when pushed by an operator or pulled by a small yard tractor.

The apparatus provided herein is a debris collector for use with a mower or a sweeper or thatcher of the rotary brush type. An important feature of the apparatus is its compression unit which includes a compression roller, chute means, and retracting fins. The hollow cylindrical compression roller mounted on said chassis is adapted for rotation about a horizontal axis. The debris confining chute is spaced from the bottom of the compression roller, forming a debris confining channel therebetween. The compression roller is provided with a series of circumferentially spaced orifices through its cylindrical surface. A stationary crankshaft is rigidly mounted on the chassis to lie eccentrically within the compression roller. A series of compacting fins is provided to move in and out of the roller surface.

Each fin has one end slidably retained within an orifice and the other end pivotally journaled to the crankshaft. The fins move in and out through the orifices on rotation of the compression roller. Means are provided at the axis of the compression roller for immovably supporting the crankshaft in an off-center position within the compression roller for maximal outward fin movement through orifices in the arc along debris conveying means to the base of the debris confining chamber, and for maximal inward fin movement in the arc from the upper portion of the debris confining chamber back to the debris conveying means. Means are also included for rotating the compression roller to drive the fins in their orifices. A debris confining chamber is positioned to receive debris forced into it by the compression role nfias- This invention thus provides a debris collector wherein each increment of debris fed into it is conveyed in compact form to a mesh or film plastic bag of the type usually for trash and leaf disposal. The brush operates equally well whether pulled by a tractor or pushed by hand. However, if desired, a unit can be fitted with its own auxiliary power unit. The cylindrical brush or broom can be the type normally used for this purpose, having a plurality of discrete brush elements mounted across a cylindrical sleeve. A modification of this brush will also be described. This and other features of the invention will be more fully understood by reference to the accompanying drawings showing several forms of the invention.

In the drawings:

FIG. 1 is a side elevational view showing the external features of one form of the invention.

FIG. 2 is a partial section showing the operation of the compression unit.

FIG. 3 is a diagrammatic representation showing the operation of the invention.

FIG. 4 is a partial view showing the compression roller and fins.

FIG. 5 is a view showing a pickup finger arrangement for the rotary sweeping unit.

FIG. 6 is a partial section showing a compression roller drive means.

FIG. 7 is a diagrammatic representation of the drive means of FIG. 6.

FIG. 8 is a diagrammatic representation of a different mhQd me f th e i Referring now further to the drawings, a machine 2 shown in FIG. 1 is provided with side panels 4 having generally arcuate top edges supported on opposite sides of the sweeper by suitable braces (not shown). A curved sheet 6 forms a cover or cage enclosing the front end of the machine. Side panels 4, cover 6, top section 8, and back section 9 form the housing for the sweeper. Supporting the housing at its base is a frame .or chassis 10. Generally, the chassis 10 is in the form of a rectangle lying in a horizontal plane. The rectangle L Y .1s n thsslirsst qngt travel-W Since the brush, the compression roller, and the drive means are all anchored to the chassis 10, the chassis 10, through wheels 12, supports the entire machine. Transversely across the front end of the chassis 10, a cylindrical brush or thatching element 14 is mounted on a shaft 16.

The shaft 16 is journaled in suitable bearings mounted on the chassis 10. One end of the shaft 16 extends beyond the chassis 10 in order to carry a driven pulley wheel 20. To afford interchangeability from brushing to thatching and vice versa, it is preferred that the brush or thatching element 14 be mounted on a sleeve 15 which locks onto the shaft 16.

It will be appreciated that means must be provided for conveying debris from the cylindrical sweeper, which includes the brush or thatching element 14, to the compression unit. Thus, a conveyor belt can pass over a roller positioned adjacent the cylindrical sweeper and carried by the chassis 10. This belt can pass around a second roller positioned near the compression unit at 23. Desirably, a chute 22 can be used for this purpose. As can be seen in FIG. 3, the chute 22 is interposed between the sweeper, which is the brush or thatching element 14, and the bottom of a compression roller 30.

Turning now to the compression unit, leaves and other debris are swept up and deposited on the chute 22. The chute 22 is inclined downwardly from its forward end adjacent the sweeping brush of thatching element 14 toward the compression roller 30. Below the compression roller 30 from 24 to 25, the debris conveying chute becomes a debris confining chute, spaced from the bottom of the compression roller 30, as shown in FIG. 3. By this arrangement, a'debris confining channel 25 is formed between the compression roller 30 and the chute 22.

In apparatus such as that described in application Ser. No. 195,607, filed Nov. 4, 1972 now abandoned, debris is compressed between rollers or a roller and a belt. Compression in the apparatus of this application is accomplished by compression fins 26, best seen in FIG. 4.

A stationary crankshaft 28 is rigidly mounted to the chassis 10 to lie eccentrically within the compression roller 30 as seen in FIGS. 2 and 3. Since the compression roller hollow drive shaft slidably surrounds the crankshaft 28 as it passes through sides of the chassis 10, the crankshaft 28 cannot be locked in the sides of the chassis 10. Accordingly, it is locked in an anchor bar 13 by means of a hub 11 being integral with the bar 13.

Suitably journaled on the crankshaft 28 through sleeve bearings 31 are the fins 26. The fins 26 are thus capable of rotation about the stationary crankshaft 28.

The compression roller 30 is provided with a plurality of orifices adapted to receive the free ends of the compression fins 26. Preferably, seated in the orifices will be bearings 32, inserted in the orifices to prevent wearing of orifice and fin surfaces as a result of the coefficient of friction therebetween.

The crankshaft 28 is immovably supported in an offcenter position within the compression roller 30 so that in their travel in the are along the debris confining 1 channel, i.e., from 25 to 24, the fins 26 extend through the bearings 32 the maximum distance at the start of the debris confining channel 25 and then move inwardly in their travel along the debris confining channel 25. As the fins 26 pass through a debris confining chamber 34, and especially under an adjustable forward wall 39 thereof, they are flush with the outside cylindrical wall of the compression roller 30, that is they have moved inwardly the maximum distance as shown in FIG. 3. FIG. 4 is a view looking down into the compression chamber. These various fin positions are readily seen in this view.

The compression roller 30 is locked on a tubular drive axle 36. The tubular compression roller drive axle 36 also carries the wheels 12. I

Because of positive one directional clutch means 40, the wheels 12 on rotation drive the compression roller axle 36 and rotate the compression drive roller 30. One clutch means shown as 40 in FIG. 2 includes drive dogs or similar slip pawl means affected by gravity so that the compression roller 30 does not rotate when the rotation of the wheels 12 is reversed. The compression roller drive axle 36 is carried in suitable bearings 37 mounted on the chassis 10.

A particularly desirable drive means is shown in FIGS. 6 and 7. A ratchet wheel 50 is rigidly secured to the tubular compression roller drive axle 36, and is thus integral with the compression roller 30, the compression roller 30 being rotated when the ratchet wheel 50 is rotated.

A pawl spindle 51 has one of its ends mounted on a hub 51' of one of the wheels 12 as shown in FIG. 6 for planetary movement about the ratchet wheel 50. The pawl spindle 51 is non-rotatably fixed to the hub 51'. The free end of the pawl spindle 51 is provided with cam surfaces 52, 53, and 54 as shown in FIG. 7.

A pawl element 55 pivotally surrounds the cam end of the spindle 51. As can be seen in FIG. 7, the pawl element 55 includes a detent 56 and a ring 57 surrounding the spindle 51. A ball 58 is urged against one of the cam surfaces by a spring 59 to frictionally lock the detent 56 in one of its three positions.

It is apparent from FIG. 7 that when the detent 56 is disposed with the ball 58 engaging the cam surface 52 the compression roller 30 will be driven counterclockwise with the counterclockwise orbital movement of the pawl spindle 51. However, by rotating the detent 56 clockwise so that the detent 56 is disposed with the ball 58 engaging the cam surface 54, the compression roller 30 can be rotated in a clockwise direction if debris should become wedged in the channel 25. This clears the obstruction.

If desired to tow the unit, the detent 56 can be disengaged from the ratchet wheel 50 so that the compression roller 30 is not driven in either direction. This is accomplished by placingnthe ball 58 against the cam surface 53.

The brush element driving means will now be described. The element 14 is driven by the wheels 12. As seen in FIG. 2, the axle 36 also carries a drive pulley wheel 42 provided with a sheave 44. The axle or shaft 16 of the brush or thatching element 14 has the driven pulley wheel 20 affixed to its end outside of the side panel 4 of the housing (FIG. 1). A brush drive belt 46 passes around and engages the aligned pulley wheels 20 and 42.

Belt tensioning is controlled and maintained by a wheel 48 slidable in an eye 50 of a plate 52. The tensioning wheel 48 is held by an axle bolt 54'. It is to be noted that the belt 46 is crossed to reverse the direction of rotation of the brush or thatching element 14 relative to the rotation of the wheels 12.

Various clamping means are available for holding a bag over the housing opening and for suspending its closed end. As described in application Ser. No. 195,607, now abandoned, a bag supporting member 72 desirably will be in the form of a U-frame having substantially parallel side members or legs 83 joined together by a crossbar 85 acoss the top. Linking means such as the ends of the anchor bars 13 extend upwardly, and the bottom ends of the side members 83 are pivotally secured to these by suitable pins so that the bag supporting frame extends upwardly away from an opening 70.

The bag is held in place over the opening 70 by a rigid band 88 (see FIG. 3) carried by the bag supporting frame legs 83 by means of brackets 89. The rigid band 88 extends outwardly from, and is almost perpendicular to, the bag supporting frame legs 83. The band 88 is either rectangular or round, being the exact shape of the opening 70 so that it is slidable thereover.

When the legs or members 83 of the bag supporting frame are urged forward toward the opening 70, the band 88 is lowered over a lip 80 seating on a rubber collar. The band 88 is unseated when the bag supporting frame is lowered away from the opening 70.

A clamping plate 93 holds the other end of a bag 92. A clamping frame, which includes arms 98 and a crossbar 100, extends upwardly and outwardly from the back of the bag supporting frame at an upwardly directed angle thereto as shown in FIG. 1.

The clamping plate 93 is carried by the clamping frame by means of bolts 101 passing through the legs 83 of the bag carrying frame to the front side. Behind and adjacent the clamping plate 93 are bag retaining members or rods 82 integral with the legs 83 of the bag supporting frame. A coil spring 103 and a similar one not shown surrounding the clamp bolts 101 urge the clamping frame cross bar 100 away from the bag supporting frame crossbar 85. This securely holds the clamping plate 93 in its normal position against the bag supported frame member 72.

It will be apparent that locking braces or similar means must be used to hold the bag supporting frame in position when the band 88 is seated over the opening 70. A preferred means for accomplishing this is to employ a retaining rod 106. Bymeans of a tab 107 (see FIG. 3) on the housing, the rod 106 is connected to the housing to pivot so that its free upper end swings over and engages the crossbar 85 of the bag supporting frame.

Any releasable latching means 108 can be used to hold the retaining rod 106 and the bag supporting frame together. Desirably a roll holder will be installed across the arms 98 of the clamping frame below the crossbar 100 to hold a roll 109 of plastic bags.

In operation, the bag 92 is locked over the opening 70 as described in conjunction with FIGS. 1 and 3, and the machine is ready for use. As will be seen, a small model can be made to be pushed by the operator. However, generally a braced tongue 74 is attached to the frame or chassis at the front of the housing. A latch type of hitch will be provided on the tongue 74 so that the machine can be connected to a small tractor or other vehicle.

The sweeper unit, which includes the brush or thatching element 14, is set to the desired height by a lever 77. The tongue 74 is jointed at the base 79 of the lever 77. This and a pivotal tractor connection permit the unit to be bent upwardly at 79 relative to the wheels 12 and the tractor hitch to raise the brush or thatching element 14. The height is adjusted by a lever 78.

When the machine is pulled forward, the wheels 12 through the one-way clutch means 40 bring about a counterclockwise rotation of the pulley wheel 42. The wheel 42 frictionally drives the belt 46, and thereby rotates the brush or thatching element 14 in a clockwise direction.

It can be seen that clockwise rotation of the brush or thatching element 14 lifts debris at the front end of the machine (FIG. 3), and discharges the debris down the chute 22. Debris sliding down the chute 22 passes into the debris channel 25 under the compression roller 30. Debris is forced through the chute 25 by the fins 26 as the compression roller 30 is driven by the rotation of the wheels 12.

As the sweeper continues to operate, the debris compression chamber 34 fills up. It has been found that the fins 26, operating as shown in FIG. 4, impart a rolling action to the debris as shown in FIG. 8. As a result of this action, the debris is tumbled into numerous tight rolls as seen at 114. Due to gravitational forces, these rolls lie side by side, and the debris is extremely well compacted in the compression chamber 34.

The rolls of debris continue accumulating in the debris confining chamber 34 as debris is forced in by the fins 26. The rolls of debris are ultimately forced through the opening by increments of debris entering the compression chamber 34 beneath it. In compacted form, the debris is gradually lifted in successive layers into the bag 92 until the bag 92 is crammed full.

This invention thus provides a sweeper which makes possible a high degree of compaction of debris. The debris bags do not have to be changed frequently, and compression of debris is achieved with very little power input.

It will be appreciated that various embodiments of this invention are possible within the spirit thereof. In its most important variation, the invention contemplates a debris collector and compressor operating without a brush. For instance, a collector of the type with a chute but no brush as shown in FIG. 4 can be positioned to receive grass cuttings from a lawn mower. It can be used to bale hay. In addition, one or more lawn mowers can be provided with tubes 112 feeding grass cuttings and leaves to the chute 22 of the apparatus as shown in FIG. 8. The debris collector can be placed directly behind a tractor or riding mower with a curved tube leading to the debris collector, or the debris collector can be positioned directly behind the mowing unit. In another embodiment of the invention, sprockets, a drive chain, and an idler gear can be employed in lieu of the pulleys and belt as the brush element drive means. As another example, instead of the cover 6, upwardly extending shields or deflecting plates can be used, leaving the conveying means exposed from the top.

As another of its embodiments, the invention contemplates that the fins 26 and the compression roller 30 can be made of any rigid material such as metal, plastic, or wood, or combinations of these materials. Likewise, the fin bearings 32 can be roller bearings, plastic sleeve bearings, etc.

It will also be obvious that variously shaped fins can be used. Instead of the fins 26 being plates, rods or strips can be used. The fins 26 are now arranged in rows spaced around the periphery of compression roller 30 as seen in FIG. 4. If the fins 26 are in the form of fingers or strips, they can be closer together. Arcuate plates, curved inwardly away from the direction of travel, also can be employed.

Another embodiment of the invention is shown in FIG. 5. In this view, arcuately arranged sweeping and thatching elements are shown. Sweeping elements which are arranged in an arc across the surface of the cylindrical sleeve on which they are mounted direct debris toward the center of the brush element and hence to the center of the chute 22. In addition, a thatching unit can be used instead of a sweeping unit or alternate stright or arcuate rows of each can be employed. However, it will generally not be necessary to do so. These and other variations will occur to those skilled in the art. Such ramifications are deemed to be within the scope of this invention.

I claim:

1. In a wheeled vehicle wherein a revolving element or the like is rotated about an axle by the wheels, drive means for rotating the revolving element in either direction and for rotating the wheels of the vehicle without rotating the revolving element comprising at least one ratchet wheel connected to the revolving element, the revolving element being rotated when said ratchet wheel is rotated, a pawl spindle mounted on at least one of the wheels of the vehicle for planetary movement about said ratchet wheel, said spindle having three cam surfaces disposed about the periphery of said spindle, a pawl element pivotally surrounding said cam surfaces of said spindle, means carried by said pawl element and frictionally bearing against one of said cam surfaces of said spindle to hold said pawl element in position, said pawl element in its first cam position engaging said ratchet wheel to rotate the revolving element in one direction as the wheels rotate forward as the vehicle is advanced and to not rotate the revolving element in the opposite direction when the wheels are rotated in reverse, said pawl elements in its second cam position engaging said ratchet wheel to rotate the revolving element in the opposite direction when the wheels are rotated in reverse and to not rotate the revolving element in the one direction when the wheels are rotated forward as the vehicle is advanced, and said pawl element in its third cam position being in disengagement from said ratchet wheel so that the wheels of the vehicle rotate either forwardly or backwardly without rotation of the revolving element.

2. The vehicle according to claim 1 in which said pawl element carried means is carried within said pawl element.

3. The vehicle according to claim 2 in which said pawl element carried means comprises spring loaded ball means, said spring loaded ball means including a ball frictionally bearing against said one cam surface of said spindle.

4. The vehicle according to claim 3 in which said spindle has said cam surfaces on its free end.

5. The vehicle according to claim 4 in which said ratchet wheel surrounds the axle of the revolving element.

6. The vehicle according to claim 1 in which said spindle has said cam surfaces on its free end.

7. The vehicle according to claim 1 in which said ratchet wheel is integral with the revolving element.

8. The vehicle according to claim 1 in which the axis of said pawl spindle is substantially parallel to the axis of rotation of the revolving element.

9. The vehicle according to claim 1 in which said cam surface engaged by said pawl element carrying means when said pawl element is in its third cam position is intermediate the other two of said cam surfaces on said spindle.

10. The vehicle according to claim 1 in which said pawl element includes a cylindrical portion surrounding said cam surfaces of said spindle and a longitudinal portion integral with said cylindrical portion and extending therefrom, said pawl element carrying means including a spring disposed within said longitudinal portion and a ball supported at one end of said spring for frictionally bearing against said one cam surface of said spindle, and said longitudinal portion engaging said ratchet wheel when said pawl element is disposed in one of its first and second cam positions.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No. 3,359,923 Dated March 11, 1975 Inv n Charles W. Doering It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 3, "AOH" should read a Column 3, line 20, "of" should read or Signed and Scaled this T weary-fourth D a) of October I 978 [SEAL] Attest:

. RUTH C MASON DONALD W. BANNER Anew-"3 017k" Commissioner of Patents and Trademarks 

1. In a wheeled vehicle wherein a revolving element or the like is rotated about an axle by the wheels, drive means for rotating the revolving element in either direction and for rotating the wheels of the vehicle without rotating the revolving element comprising at least one ratchet wheel connected to the revolving element, the revolving element being rotated when said ratchet wheel is rotated, a pawl spindle mounted on at least one of the wheels of the vehicle for planetary movement about said ratchet wheel, said spindle having three cam surfaces disposed about the periphery of said spindle, a pawl element pivotally surrounding said cam surfaces of said spindle, means carried by said pawl element and frictionally bearing against one of said cam surfaces of said spindle to hold said pawl element in position, said pawl element in its first cam position engaging said ratchet wheel to rotate the revolving element in one direction as the wheels rotate forward as the vehicle is advanced and to not rotate the revolving element in the opposite direction when the wheels are rotated in reverse, said pawl elements in its second cam position engaging said ratchet wheel to rotate the revolving element in the opposite direction when the wheels are rotated in reverse and to not rotate the revolving element in the one direction when the wheels are rotated forward as the vehicle is advanced, and said pawl element in its third cam position being in disengagement from said ratchet wheel so that the wheels of the vehicle rotate either forwardly or backwardly without rotation of the revolving element.
 1. In a wheeled vehicle wherein a revolving element or the like is rotated about an axle by the wheels, drive means for rotating the revolving element in either direction and for rotating the wheels of the vehicle without rotating the revolving element comprising at least one ratchet wheel connected to the revolving element, the revolving element being rotated when said ratchet wheel is rotated, a pawl spindle mounted on at least one of the wheels of the vehicle for planetary movement about said ratchet wheel, said spindle having three cam surfaces disposed about the periphery of said spindle, a pawl element pivotally surrounding said cam surfaces of said spindle, means carried by said pawl element and frictionally bearing against one of said cam surfaces of said spindle to hold said pawl element in position, said pawl element in its first cam position engaging said ratchet wheel to rotate the revolving element in one direction as the wheels rotate forward as the vehicle is advanced and to not rotate the revolving element in the opposite direction when the wheels are rotated in reverse, said pawl elements in its second cam position engaging said ratchet wheel to rotate the revolving element in the opposite direction when the wheels are rotated in reverse and to not rotate the revolving element in the one direction when the wheels are rotated forward as the vehicle is advanced, and said pawl element in its third cam position being in disengagement from said ratchet wheel so that the wheels of the vehicle rotate either forwardly or backwardly without rotation of the revolving element.
 2. The vehicle according tO claim 1 in which said pawl element carried means is carried within said pawl element.
 3. The vehicle according to claim 2 in which said pawl element carried means comprises spring loaded ball means, said spring loaded ball means including a ball frictionally bearing against said one cam surface of said spindle.
 4. The vehicle according to claim 3 in which said spindle has said cam surfaces on its free end.
 5. The vehicle according to claim 4 in which said ratchet wheel surrounds the axle of the revolving element.
 6. The vehicle according to claim 1 in which said spindle has said cam surfaces on its free end.
 7. The vehicle according to claim 1 in which said ratchet wheel is integral with the revolving element.
 8. The vehicle according to claim 1 in which the axis of said pawl spindle is substantially parallel to the axis of rotation of the revolving element.
 9. The vehicle according to claim 1 in which said cam surface engaged by said pawl element carrying means when said pawl element is in its third cam position is intermediate the other two of said cam surfaces on said spindle. 